Use of thermoplastic molding materials for GID/WIT

ABSTRACT

Use of thermoplastic molding compositions comprising
     A) from 10 to 89% by weight of a polyethylene terephthalate which can comprise up to 65% by weight, based on 100% by weight of A), of another polyester,   B) from 0.01 to 50% by weight of   B1) at least one highly branched or hyperbranched polycarbonate with an OH number of from 1 to 600 mg KOH/g of polycarbonate (to DIN 53240, part 2), or   B2) at least one highly branched or hyperbranched polyester of A x B y  type, where x is at least 1.1 and y is at least 2.1,
       or a mixture of these,   
       C) from 10 to 60% by weight of a fibrous or particulate filler, and   D) from 0 to 20% by weight of further additives,
 
where the total of the percentages by weight of components A) to D) is 100%, for the production of moldings by means of the internal-gas-pressure process and/or the water-injection process.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of application Ser. No.12/743,530, filed May 18, 2010 now abandoned, which is a national stageapplication under 35 U.S.C. §371 of PCT/EP2008/065763, filed Nov. 18,2008, which claims benefit to European application 07121118.9, filedNov. 20, 2007, the entire disclosures of all of which are herebyincorporated by reference.

The invention relates to the use of thermoplastic molding materialscomprising

-   A) from 10 to 89% by weight of a polyethylene terephthalate which    can comprise up to 65% by weight, based on 100% by weight of A), of    another polyester,-   B) from 0.01 to 50% by weight of-   B1) at least one highly branched or hyperbranched polycarbonate with    an OH number of from 1 to 600 mg KOH/g of polycarbonate (to DIN    53240, part 2), or-   B2) at least one highly branched or hyperbranched polyester of    A_(x)B_(y) type, where x is at least 1.1 and y is at least 2.1,    -   or a mixture of these,-   C) from 10 to 60% by weight of a fibrous or particulate filler, and-   D) from 0 to 20% by weight of further additives,    where the total of the percentages by weight of components A) to D)    is 100%, for the production of moldings by means of the    internal-gas-pressure process and/or the water-injection process.

Low-molecular-weight additives are usually added to thermoplastics, toimprove flowability. However, the effect of these additives is subjectto severe restriction, since, by way of example, the fall-off ofmechanical properties becomes unacceptable when the amount of theadditive added is increased.

Dendritic polymers having a perfectly symmetrical structure, known asdendrimers, can be prepared starting from one central molecule viacontrolled stepwise linkage of, in each case, two or more di- orpolyfunctional monomers to each previously bonded monomer. Each linkagestep here exponentially increases the number of monomer end groups (andtherefore of linkages), and this gives polymers with dendriticstructures, in the ideal case spherical, each of the branches of whichcomprises exactly the same number of monomer units. This perfectstructure provides advantageous polymer properties, and by way ofexample surprisingly low viscosity is found, as is high reactivity, dueto the large number of functional groups on the surface of the sphere.However, the preparation process is complicated by the fact thatprotective groups have to be introduced and in turn removed again duringeach linkage step, and purification operations are required, the resultbeing that it is usual for dendrimers to be prepared only on alaboratory scale.

In contrast, it is easy to prepare highly branched or hyperbranchedpolymers by using industrial processes. They also have linear polymerchains and unequal polymer branches alongside perfect dendriticstructures, but often this does not substantially impair the propertiesof the polymer when comparison is made with the properties of perfectdendrimers. Hyperbranched polymers can be prepared via two syntheticroutes known as AB₂ and A_(x)+B_(y). A_(x) and B_(y) here are differentmonomers and the indices x and y are the number of functional groupspresent in A and B respectively, i.e. the functionality of A and B,respectively. In the AB₂ route, a trifunctional monomer having areactive group A and having two reactive groups B is reacted to give ahighly branched or hyperbranched polymer. In the A_(x) and B_(y)synthesis, taking the example of A₂+B₃ synthesis, a difunctional monomerA₂ is reacted with a trifunctional monomer B₃. This first gives a 1:1adduct composed of A and B having an average of one functional group Aand two functional groups B, and this can then likewise react to give ahighly branched or hyperbranched polymer.

WO-97/45474 discloses thermoplastic compositions which comprisedendrimeric polyesters as AB₂ molecule. Here, a polyhydric alcohol ascore molecule reacts with dimethylolpropionic acid as AB₂ molecule togive a dendrimeric polyester. This comprises only OH functions at theend of the chain. Disadvantages of these mixtures are high glasstransition temperature of the dendrimeric polyesters, comparativelycomplicated preparation process, and especially poor solubility of thedendrimers in the polyester matrix.

According to the teaching of DE-A 101 32 928, the incorporation ofbranching agents of this type by means of compounding and solid-phasepost-condensation leads to an improvement in mechanical properties(molecular weight increase). The disadvantages of the process variantdescribed are long preparation time and the disadvantageous propertieslisted above.

WO 2005/075565 and WO 2005/075563 have previously proposed noveladditives for flow improvement for polyesters. Because of thesubstantially slower crystallization behavior of PET, it is important toimprove processing performance for specific applications, in particularin the case of polyester molding compositions which have high fillercontent (high stiffness).

It was therefore an object of the present invention to providethermoplastic molding compositions which have good flowability andsimultaneously very high stiffness and strength.

A further intention was that the polyester molding compositions have agood and uniform surface (minimum number of “voids”) where moldings areproduced by the gas- or water-injection process, and permit good coatingwith, for example, powder coatings at high temperatures.

Accordingly, the uses defined in the introduction have been found formolding compositions. The subclaims give preferred uses.

The molding compositions that can be used according to the inventioncomprise, as component (A), from 10 to 89% by weight, preferably from 10to 69% by weight, and in particular from 10 to 59% by weight, of atleast one thermoplastic PET (polyethylene terephthalate).

This PET can comprise up to 65% by weight, based on 100% by weight ofA), preferably up to 30% by weight, of another polyester which differsfrom PET.

Use is generally made of polyesters A) based on aromatic dicarboxylicacids and on an aliphatic or aromatic dihydroxy compound.

A first group of preferred polyesters is that of polyalkyleneterephthalates, in particular those having from 2 to 10 carbon atoms inthe alcohol moiety.

Polyalkylene terephthalates of this type are known per se and aredescribed in the literature. Their main CHAIN comprises an aromatic ringwhich derives from the aromatic dicarboxylic acid. There may also besubstitution in the aromatic ring, e.g. by halogen, such as chlorine orbromine, or by C₁-C₄-alkyl groups, such as methyl, ethyl, iso- orn-propyl, or n-, iso- or tert-butyl groups.

These polyalkylene terephthalates may be prepared by reacting aromaticdicarboxylic acids, or their esters or other ester-forming derivatives,with aliphatic dihydroxy compounds in a manner known per se.

Preferred dicarboxylic acids are 2,6-naphthalenedicarboxylic acid,terephthalic acid and isophthalic acid, and mixtures of these. Up to 30mol %, preferably not more than 10 mol %, of the aromatic dicarboxylicacids may be replaced by aliphatic or cycloaliphatic dicarboxylic acids,such as adipic acid, azelaic acid, sebacic acid, dodecanedioic acids andcyclohexanedicarboxylic acids.

Preferred aliphatic dihydroxy compounds are diols having from 2 to 6carbon atoms, in particular 1,2-ethanediol, 1,3-propanediol,1,4-butanediol, 1,6-hexanediol, 1,4-hexanediol, 1,4-cyclohexanediol,1,4-cyclohexanedimethanol and neopentyl glycol, and mixtures of these.

Particularly preferred polyesters (A) are polyalkylene terephthalatesderived from alkanediols having from 2 to 6 carbon atoms. Among these,particular preference is given to polyethylene terephthalate,polypropylene terephthalate and polybutylene terephthalate, end mixturesof these. Preference is also given to PET and/or PBT which comprise, asother monomer drifts, up to 1% by weight, preferably up to 0.75% byweight, of 1,6-hexanediol and/or 2-methyl-1,5-pentanediol.

The viscosity number of the polyesters (A) is generally in the rangefrom 50 to 220, preferably from 80 to 160 (measured in 0.5% strength byweight solution in a phenol/o-dichlorobenzene mixture in a weight ratioof 1:1 at 25° C.) in accordance with ISO 1628.

Particular preference is given to polyesters whose carboxy end groupcontent is up to 100 meq/kg of polyester, preferably up to 50 meq/kg ofpolyester and in particular up to 40 meq/kg of polyester. Polyesters ofthis type may be prepared, for example, by the process of DE-A 44 01055. The carboxy end group content is usually determined by titrationmethods (e.g. potentiometry).

It is also advantageous to use recycled PET materials (also termed scrapPET), if appropriate mixed with polyalkylene terephthalates, such asPBT.

Recycled materials are generally:

-   1) those known as post-industrial recycled materials: these are    production wastes during polycondensation or during processing, e.g.    sprues from injection molding, start-up material from injection    molding or extrusion, or edge trims, from extruded sheets or foils.-   2) post-consumer recycled materials: these are plastic items which    are collected and treated after utilization by the end consumer.    Blow-molded PET bottles for mineral water, soft drinks and juices    are easily the predominant items in terms of quantity.

The two types of recycled material may be present either as groundmaterial or in the form of pellets. In the latter case, the cruderecycled materials are separated and purified and then melted andpelletized using an extruder. This usually facilitates handling and freeflow, and metering for further steps in processing.

The recycled materials used may be either pelletized or in the form ofregrind. The edge length should not be more than 10 mm, preferably lessthan 8 mm.

Because polyesters undergo hydrolytic cleavage during processing (due totraces of moisture) it is advisable to predry the recycled material. Theresidual moisture content after drying is preferably <0.2%, inparticular <0.05%.

Another group to be mentioned is that of fully aromatic polyestersderived from aromatic dicarboxylic acids and aromatic dihydroxycompounds.

Suitable aromatic dicarboxylic acids are the compounds previouslydescribed for the polyalkylene terephthalates. The mixtures preferablyused are composed of from 5 to 100 mol % of isophthalic acid and from 0to 95 mol % of terephthalic acid, in particular from about 50 to about80% of terephthalic acid and from about 20 to about 50% of isophthalicacid.

The aromatic dihydroxy compounds preferably have the general formula,

where Z is an alkylene or cycloalkylene group having up to 8 carbonatoms, an arylene group having up to 12 carbon atoms, a carbonyl group,a sulfonyl group, an oxygen or sulfur atom, or a chemical bond, and m isfrom 0 to 2. The phenylene groups of the compounds may also havesubstitution by C₁-C₆-alkyl or alkoxy groups and fluorine, chlorine orbromine.

Examples of parent compounds for these compounds are

-   dihydroxybiphenyl,-   di(hydroxyphenyl)alkane,-   di(hydroxyphenyl)cycloalkane,-   di(hydroxyphenyl)sulfide,-   di(hydroxyphenyl)ether,-   di(hydroxyphenyl)ketone,-   di(hydroxyphenyl)sulfoxide,-   α,α′-di(hydroxyphenyl)dialkylbenzene,-   di(hydroxyphenyl)sulfone, di(hydroxybenzoyl)benzene,-   resorcinol, and    hydroquinone, and also the ring-alkylated and ring-halogenated    derivatives of these.

Among these, preference is given to

-   4,4′-dihydroxybiphenyl,-   2,4-di(4′-hydroxyphenyl)-2-methylbutane,-   α,α′-di(4-hydroxyphenyl)-p-diisopropylbenzene,-   2,2-di(3′-methyl-4′-hydroxyphenyl)propane, and-   2,2-di(3′-chloro-4′-hydroxyphenyl)propane,    and in particular to-   2,2-di(4′-hydroxyphenyl)propane-   2,2-di(3′,5-dichlorodihydroxyphenyl)propane,-   1,1-di(4′-hydroxyphenyl)cyclohexane,-   3,4′-dihydroxybenzophenone,-   4,4′-dihydroxydiphenyl sulfone and-   2,2-(3′,5′-dimethyl-4′-hydroxyphenyl)propane    and mixtures of these.

It is, of course, also possible to use mixtures of polyalkyleneterephthalates and fully aromatic polyesters. These generally comprisefrom 20 to 98% by weight of the polyalkylene terephthalate and from 2 to80% by weight of the fully aromatic polyester.

It is, of course, also possible to use polyester block copolymers, suchas copolyetheresters. Products of this type are known per se and aredescribed in the literature, e.g. in U.S. Pat. No. 3,651,014.Corresponding products are also available commercially, e.g. Hytrel®(DuPont).

According to the invention, polyesters include halogen-freepolycarbonates. Examples of suitable halogen-free polycarbonates arethose based on diphenols of the general formula

where Q is a single bond, a C₁-C₈-alkylene group, a C₂-C₃-alkylidenegroup, a C₃-C₆-cycloalkylidene group, a C₆-C₁₂-arylene group, or else—O—, —S—, or —SO₂—, and m is a whole number from 0 to 2.

The phenylene radicals of the diphenols may also have substituents, suchas C₁-C₆-alkyl or C₁-C₆-alkoxy.

Examples of preferred diphenols of the formula are hydroquinone,resorcinol, 4,4′-dihydroxybiphenyl, 2,2-bis(4-hydroxyphenyl)propane,2,4-bis(4-hydroxyphenyl)-2-methylbutane and1,1-bis(4-hydroxyphenyl)cyclohexane. Particular preference is given to2,2-bis(4-hydroxyphenyl)propane and 1,1-bis(4-hydroxyphenyl)cyclohexane,and also to 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane.

Either homopolycarbonates or copolycarbonates are suitable as componentA, and preference is given to the copolycarbonates of bisphenol A, aswell as to bisphenol A homopolymer.

Suitable polycarbonates may be branched in a known manner, specificallyand preferably by incorporating from 0.05 to 2.0 mol %, based on thetotal of the diphenols used, of at least trifunctional compounds, forexample those having three or more phenolic OH groups.

Polycarbonates which have proven particularly suitable have relativeviscosities η_(rel) of from 1.10 to 1.50, in particular from 1.25 to1.40. This corresponds to an average molar mass M_(w) (weight-average)of from 10 000 to 200 000 g/mol, preferably from 20 000 to 80 000 g/mol.

The diphenols of the general formula are known per se or can be preparedby known processes.

The polycarbonates may, for example, be prepared by reacting thediphenols with phosgene in the interfacial process, or with phosgene inthe homogeneous-phase process (known as the pyridine process), and ineach case the desired molecular weight is achieved in a known manner byusing an appropriate amount of known chain terminators. (In relation topolydiorganosiloxane-containing polycarbonates see, for example, DE-A 3334 782.)

Examples of suitable chain terminators are phenol, p-tert-butylphenol,or else long-chain alkylphenols, such as 4-(1,3-tetramethylbutyl)phenolas in DE-A 28 42 005, or monoalkylphenols, or dialkylphenols with atotal of from 8 to 20 carbon atoms in the alkyl substituents as inDE-A-35 06 472, such as p-nonylphenol, 3,5-di-tert-butylphenol,p-tert-octylphenol, p-dodecylphenol, 2-(3,5-dimethylheptyl)phenol and4-(3,5-dimethylheptyl)phenol.

For the purposes of the present invention, halogen-free polycarbonatesare polycarbonates composed of halogen-free diphenols, of halogen-freechain terminators and, if used, halogen-free branching agents, where thecontent of subordinate amounts at the ppm level of hydrolyzablechlorine, resulting, for example, from the preparation of thepolycarbonates with phosgene in the interfacial process, is not regardedas meriting the term halogen-containing for the purposes of theinvention. Polycarbonates of this type with contents of hydrolyzablechlorine at the ppm level are halogen-free polycarbonates for thepurposes of the present invention.

Other suitable components A) which may be mentioned are amorphouspolyester carbonates, where during the preparation process phosgene hasbeen replaced by aromatic dicarboxylic acid units, such as isophthalicacid and/or terephthalic acid units. Reference may be made at this pointto EP-A 711 810 for further details.

EP-A 365 916 describes other suitable copolycarbonates having cycloalkylradicals as monomer units.

It is also possible for bisphenol A to be replaced by bisphenol TMC.Polycarbonates of this type are obtainable from Bayer with the trademarkAPEC HT®.

The molding compositions which can be used according to the inventioncomprise, as component B), from 0.01 to 50% by weight, preferably from0.1 to 10% by weight, and in particular from 0.1 to 5% by weight, of B1)at least one highly branched or hyperbranched polycarbonate, with an OHnumber of from 1 to 600 mg KOH/g of polycarbonate, with preference from10 to 550 mg KOH/g of polycarbonate, and in particular from 50 to 550 mgKOH/g of polycarbonate (to DIN 53240, part 2), or of at least onehyperbranched polyester as component B2), or a mixture of these, asexplained below.

For the purposes of this invention, hyperbranched polycarbonates B1) arenon-crosslinked macromolecules having hydroxy groups and carbonategroups, these having both structural and molecular non-uniformity. Theirstructure may firstly be based on a central molecule in the same way asdendrimers, but with non-uniform chain length of the branches. Secondly,they may also have a linear structure with functional pendant groups, orelse they may combine the two extremes, having linear and branchedmolecular portions. See also P. J. Flory, J. Am. Chem. Soc. 1952, 74,2718, and H. Frey et al., Chem. Eur. J. 2000, 6, no. 14, 2499 for thedefinition of dendrimeric and hyperbranched polymers.

“Hyperbranched” in the context of present invention means that thedegree of branching (DB), i.e. the average number of dendritic linkages,plus the average number of end groups per molecule, is from 10 to 99.9%,preferably from 20 to 99%, particularly preferably from 20 to 95%.

“Dendrimeric” in the context of the present invention means that thedegree of branching is from 99.9 to 100%. See H. Frey et al., ActaPolym. 1997, 48, 30 for the definition of “degree of branching”.

The DB (degree of branching) of the relevant substances is defined as

${{DB} = {\frac{T + Z}{T + Z + L} \times 100\%}},$(where T is the average number of terminal monomer units, Z is theaverage number of branched monomer units, and L is the average number oflinear monomer units in the macromolecules of the respectivesubstances).

Component B1) preferably has a number-average molar mass M_(n) of from100 to 15 000 g/mol, preferably from 200 to 12 000 g/mol, and inparticular from 500 to 10 000 g/mol (GPC, PMMA standard).

The glass transition temperature Tg is in particular from −80° C. to+140° C., preferably from −60 to 120° C. (according to DSC, DIN 53765).

In particular, the viscosity (mPas) at 23° C. (to DIN 53019) is from 50to 200 000, in particular from 100 to 150 000, and very particularlypreferably from 200 to 100 000.

Component B1) is preferably obtainable via a process which comprises atleast the following steps:

-   a) reaction of at least one organic carbonate (A) of the general    formula RO[(CO)]_(n)OR with at least one aliphatic,    aliphatic/aromatic or aromatic alcohol (B) which has at least 3 OH    groups, with elimination of alcohols ROH to give one or more    condensates (K), where each R, independently of the others, is a    straight-chain or branched aliphatic, aromatic/aliphatic or aromatic    hydrocarbon radical having from 1 to 20 carbon atoms, and where the    radicals R may also have bonding to one another to form a ring, and    n is a whole number from 1 to 5, or-   ab) reaction of phosgene, diphosgene, or triphosgene with    abovementioned alcohol (B), with elimination of hydrogen chloride,    -   and-   b) intermolecular reaction of the condensates (K) to give a highly    functional, highly branched, or highly functional, hyperbranched    polycarbonate,    where the quantitative proportion of the OH groups to the carbonates    in the reaction mixture is selected in such a way that the    condensates (K) have an average of either one carbonate group and    more than one OH group or one OH group and more than one carbonate    group.

Phosgene, diphosgene, or triphosgene may be used as starting material,but preference is given to organic carbonates.

Each of the radicals R of the organic carbonates (A) used as startingmaterial and having the general formula RO(CO)OR is, independently ofthe others, a straight-chain or branched aliphatic, aromatic/aliphaticor aromatic hydrocarbon radical having from 1 to 20 carbon atoms. Thetwo radicals R may also have bonding to one another to form a ring. Theradical is preferably an aliphatic hydrocarbon radical, and particularlypreferably a straight-chain or branched alkyl radical having from 1 to 5carbon atoms, or a substituted or unsubstituted phenyl radical.

In particular, use is made of simple carbonates of the formulaRO(CO)_(n)OR; n is preferably from 1 to 3, in particular 1.

By way of example, dialkyl or diaryl carbonates may be prepared from thereaction of aliphatic, araliphatic, or aromatic alcohols, preferablymonoalcohols, with phosgene. They may also be prepared by way ofoxidative carbonylation of the alcohols or phenols by means of CO in thepresence of noble metals, oxygen, or NO_(x). In relation to preparationmethods for diaryl or dialkyl carbonates, see also “Ullmann'sEncyclopedia of Industrial Chemistry”, 6th edition, 2000 ElectronicRelease, Verlag Wiley-VCH.

Examples of suitable carbonates comprise aliphatic, aromatic/aliphaticor aromatic carbonates, such as ethylene carbonate, propylene 1,2- or1,3-carbonate, diphenyl carbonate, ditolyl carbonate, dixylyl carbonate,dinaphthyl carbonate, ethyl phenyl carbonate, dibenzyl carbonate,dimethyl carbonate; diethyl carbonate; dipropyl carbonate, dibutylcarbonate, diisobutyl carbonate, dipentyl carbonate; dihexyl carbonate,dicyclohexyl carbonate, diheptyl carbonate, dioctyl carbonate, didecylcarbonate, or didodecyl carbonate.

Examples of carbonates where n is greater than 1 comprise dialkyldicarbonates, such as di(tert-butyl)dicarbonate, or dialkyltricarbonates, such as di(tert-butyl)tricarbonate.

It is preferable to use aliphatic carbonates, in particular those inwhich the radicals comprise from 1 to 5 carbon atoms, e.g. dimethylcarbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, ordiisobutyl carbonate.

The organic carbonates are reacted with at least one aliphatic alcohol(B) which has at least 30H groups, or with mixtures of two or moredifferent alcohols.

Examples of compounds having at least three OH groups comprise glycerol,trimethylolmethane, trimethylolethane, trimethylolpropane;1,2,4-butanetriol, tris(hydroxymethyl)amine, tris(hydroxyethyl)amine,tris(hydroxypropyl)amine, pentaerythritol, diglycerol, triglycerol,polyglycerols, tris(hydroxymethyl)isocyanurate,tris(hydroxyethyl)isocyanurate, phloroglucinol, trihydroxytoluene,trihydroxydimethylbenzene; phloroglucides, hexahydroxybenzene,1,3,5-benzenetrimethanol, 1,1,1-tris(4′-hydroxyphenyl)methane,1,1,1-tris(4′-hydroxyphenyl)ethane, bis(trimethylolpropane), or sugars,e.g. glucose, trihydric or higher polyhydric polyetherols based ontrihydric or higher polyhydric alcohols and ethylene oxide, propyleneoxide, or butylene oxide, or polyesterols. Particular preference isgiven here to glycerol, trimethylolethane, trimethylolpropane,1,2,4-butanetriol, pentaerythritol, and also their polyetherols based onethylene oxide or propylene oxide.

These polyhydric alcohols may also be used in a mixture with dihydricalcohols (B′), with the proviso that the average total OH functionalityof all of the alcohols used is greater than 2. Examples of suitablecompounds having two OH groups comprise ethylene glycol, diethyleneglycol, triethylene glycol, 1,2- and 1,3-propanediol,dipropylene-glycol, tripropylene glycol, neopentyl glycol, 1,2-, 1,3-,and 1,4-butanediol, 1,2-, 1,3-, and 1,5-pentanediol, hexanediol,cyclopentanediol, cyclohexanediol, cyclohexanedimethanol,bis(4-hydroxycyclohexyl)methane, bis(4-hydroxycyclohexyl)ethane,2,2-bis(4-hydroxycyclohexyl)propane,1,1′-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, resorcinol,hydroquinone, 4,4′-dihydroxyphenyl, bis(4-bis(hydroxyphenyl)sulfide,bis(4-hydroxyphenyl)sulfone, bis(hydroxymethyl)benzene,bis-(hydroxymethyl)toluene, bis(p-hydroxyphenyl)methane,bis(p-hydroxyphenyl)ethane, 2,2-bis(p-hydroxyphenyl)propane,1,1-bis(p-hydroxyphenyl)cyclohexane, dihydroxybenzophenone, dihydricpolyether polyols based on ethylene oxide, propylene oxide, butyleneoxide, or mixtures of these, polytetrahydrofuran, polycaprolactone, orpolyesterols based on diols and dicarboxylic acids.

The diols serve for fine adjustment of the properties of thepolycarbonate. If use is made of dihydric alcohols, the ratio ofdihydric alcohols B′) to the at least trihydric alcohols (B) is set bythe person skilled in the art and depends on the desired properties ofthe polycarbonate. The amount of the alcohol(s) (B′) is generally from 0to 39.9 mol %, based on the total amount of all of the alcohols (B) and(B′) taken together. The amount is preferably from 0 to 35 mol %,particularly preferably from 0 to 25 mol %, and very particularlypreferably from 0 to 10 mol %.

The reaction of phosgene, diphosgene, or triphosgene with the alcohol oralcohol mixture generally takes place with elimination of hydrogenchloride, and the reaction of the carbonates with the alcohol or alcoholmixture to give the inventive highly functional highly branchedpolycarbonate takes place with elimination of the monofunctional alcoholor phenol from the carbonate molecule.

The highly functional highly branched polycarbonates formed by theinventive process have termination by hydroxy groups and/or by carbonategroups after the reaction, i.e. with no further modification. They havegood solubility in various solvents, e.g. in water, alcohols, such asmethanol, ethanol, butanol, alcohol/water mixtures, acetone, 2-butanone,ethyl acetate, butyl acetate, methoxypropyl acetate, methoxyethylacetate, tetrahydrofuran, dimethylformamide, dimethylecetamide,N-methylpyrrolidone, ethylene carbonate, or propylene carbonate.

For the purposes of this invention, a highly functional polycarbonate isa product which, besides the carbonate groups which form the polymerskeleton, further has at least three, preferably at least six, morepreferably at least ten, terminal or pendant functional groups. Thefunctional groups are carbonate groups and/or OH groups. There is inprinciple no upper restriction on the number of the terminal or pendantfunctional groups, but products having a very high number of functionalgroups can have undesired properties, such as high viscosity or poorsolubility. The highly functional polycarbonates of the presentinvention mostly have not more than 500 terminal or pendant functionalgroups, preferably not more than 100 terminal or pendant functionalgroups.

When preparing the highly functional polycarbonates B1), it is necessaryto adjust the ratio of the compounds comprising OH groups to phosgene orcarbonate in such a way that the simplest resultant condensate(hereinafter termed condensate (K)) comprises an average of either onecarbonate group or carbamoyl group and, more than one OH group or one OHgroup and more than one carbonate group or carbamoyl, group. Thesimplest structure of the condensate (K) composed of a carbonate (A) anda di- or polyalcohol (B) here results in the arrangement XY_(n) orY_(n)X, where X is a carbonate group, Y is a hydroxy group, and n isgenerally a number from 1 to 6, preferably from 1 to 4, particularlypreferably from 1 to 3. The reactive group which is the single resultantgroup here is generally termed “focal group” below.

By way of example, if during the preparation of the simplest condensate(K) from a carbonate and a dihydric alcohol the reaction ratio is 1:1,the average result is a molecule of XY type, illustrated by the generalformula 1.

During, the preparation of the condensate (K) from a carbonate and atrihydric alcohol with a reaction ratio of 1:1, the average result is amolecule of XY₂ type, illustrated by the general formula 2. A carbonategroup is focal group here.

During the preparation of the condensate (K) from a carbonate and atetrahydric alcohol, likewise with the reaction ratio 1:1, the averageresult is a molecule of XY₃ type, illustrated by the general formula 3.A carbonate group is focal group here:

R in the formulae 1-3 has the definition given at the outset, and R′ isan aliphatic or aromatic radical.

The condensate (K) may, by way of example, also be prepared from acarbonate and a trihydric alcohol, as illustrated by the general formula4, the molar reaction ratio being 2:1. Here, the average result is amolecule of X₂Y type, an OH group being focal group here. In formula 4,R and R¹ are as defined in formulae 1-3.

If difunctional compounds, e.g. a dicarbonate or a diol, are also addedto the components, this extends the chains, as illustrated by way ofexample in the general formula 5. The average result is again a moleculeof XY₂ type, a carbonate group being focal group.

In formula 5, R² is an organic, preferably aliphatic radical, and R andR¹ are as defined above.

It is also possible to use two or more condensates (K) for thesynthesis. Here, firstly two or more alcohols or two or more carbonatesmay be used. Furthermore, mixtures of various condensates of differentstructure can be obtained via the selection of the ratio of the alcoholsused and of the carbonates or the phosgenes. This May be illustratedtaking the example of the reaction of a carbonate with a trihydricalcohol. If the starting products are used in a ratio of 1:1, as shownin (II), the result is an XY₂ molecule. If the starting products areused in a ratio of 2:1, as shown in (IV), the result is an X₂Y molecule.If the ratio is from 1:1 to 2:1, the result is a mixture of XY₂ and X₂Ymolecules.

According to the invention, the simple condensates (K) described by wayof example in the formulae 1-5 preferentially react intermolecularly toform highly functional polycondensates, hereinafter termedpolycondensates (P). The reaction to give the condensate (K) and to givethe polycondensates (P) usually takes place at a temperature of from 0to 250° C., preferably from 60 to 160° C., in bulk or in solution. Usemay generally be made here of any of the solvents which are inert withrespect to the respective starting materials. Preference is given to useof organic solvents, e.g. decane, dodecane, benzene, toluene,chlorobenzene; xylene, dimethylformamide, dimethylacetamide, or solventnaphtha.

In one preferred embodiment, the condensation reaction is carried out inbulk. To accelerate the reaction, the phenol or the monohydric alcoholROH liberated during the reaction can be removed by distillation fromthe reaction equilibrium if appropriate at reduced pressure.

If removal by distillation is intended, it is generally advisable to usethose carbonates which liberate alcohols ROH with a boiling point below140° C. during the reaction.

Catalysts or catalyst mixtures may also be added to accelerate thereaction. Suitable catalysts are compounds which catalyze esterificationor transesterification reactions, e.g. alkali metal hydroxides, alkalimetal carbonates, alkali metal hydrogencarbonates, preferably of sodium,of potassium, or of cesium, tertiary amines, guanidines, ammoniumcompounds, phosphonium compounds, organoaluminum, organotin, organozinc,organotitanium, organozirconium, or organobismuth compounds, or elsewhat are known as double metal cyanide (DMC) catalysts, e.g. asdescribed in DE 10138216 or DE 10147712.

It is preferable to use potassium hydroxide, potassium carbonate,potassium hydrogencarbonate, diazabicyclooctane (DABCO),diazabicyclononene (DBN), diazabicycloundecene (DBU), imidazoles, suchas imidazole, 1-methylimidazole, or 1,2-dimethylimidazole, titaniumtetrabutoxide, titanium tetraisopropoxide, dibutyltin oxide, dibutyltindilaurate, stannous dioctoate, zirconium acetylacetonate, or mixturesthereof.

The amount of catalyst generally added is from 50 to 10 000 ppm byweight, preferably from 100 to 5000 ppm by weight, based on the amountof the alcohol mixture or alcohol used.

It is also possible to control the intermolecular polycondensationreaction via addition of the suitable catalyst or else via selection ofa suitable temperature. The average molecular weight of the polymer (P)may moreover be adjusted by way of the composition of the startingcomponents and by way of the residence time.

The condensates (K) and the polycondensates (P) prepared at an elevatedtemperature are usually stable at room temperature for a relatively longperiod.

The nature of the condensates (K) permits polycondensates (P) withdifferent structures to result from the condensation reaction, thesehaving branching but no crosslinking. Furthermore, in the ideal case,the polycondensates (P) have either one carbonate group as focal groupand more than two OH groups or else one OH group as focal group and morethan two carbonate groups. The number of the reactive groups here is theresult of the nature of the condensates (K) used and the degree ofpolycondensation.

By way of example, a condensate (K) according to the general formula 2can react via triple intermolecular condensation to give two differentpolycondensates (P), represented in the general formulae 6 and 7.

In formula 6 and 7, R and R¹ are as defined above.

There are various ways of terminating the intermolecularpolycondensation reaction. By way of example, the temperature may belowered to a range where the reaction stops and the product (K) or thepolycondensate (P) is storage-stable.

It is also possible to deactivate the catalyst, for example in the case,of basic catalysts via addition of Lewis acids or protic acids.

In another embodiment, as soon as the intermolecular reaction of thecondensate (K) has produced a polycondensate (P) with the desired degreeof polycondensation, a product having groups reactive toward the focalgroup of (P) may be added to the product (P) to terminate the reaction.In the case of a carbonate group as focal group, by way of example, amono-, di-, or polyamine may be added. In the case of a hydroxy group asfocal group, by way of example, a mono-, di-, or polyisocyanate, or acompound comprising epoxy groups, or an acid derivative which reactswith OH groups, can be added to the product (P).

The inventive highly functional polycarbonates are mostly prepared inthe pressure range from 0.1 mbar to 20 bar, preferably at from 1 mbar to5 bar, in reactors or reactor cascades which are operated batchwise,semicontinuously, or continuously.

The inventive products can be further processed without furtherpurification after their preparation by virtue of the abovementionedadjustment of the reaction conditions and, if appropriate, by virtue ofthe selection of the suitable solvent.

In another preferred embodiment, the product is stripped, i.e. freedfrom low-molecular-weight, volatile compounds. For this, once thedesired degree of conversion has been reached the catalyst mayoptionally be deactivated and the low-molecular-weight volatileconstituents, e.g. monoalcohols, phenols, carbonates, hydrogen chloride,or volatile oligomeric or cyclic compounds; can be removed bydistillation, if appropriate with introduction of a gas, preferablynitrogen, carbon dioxide, or air, if appropriate at reduced pressure.

In another preferred embodiment, the inventive polycarbonates maycomprise other functional groups besides the functional groups presentat this stage by virtue of the reaction. The functionalization may takeplace during the process to increase molecular weight, or elsesubsequently, i.e. after completion of the actual polycondensation.

If, prior to or during the process to increase molecular weight,components are added which have other functional groups or functionalelements besides hydroxy or carbonate groups, the result is apolycarbonate polymer with randomly distributed functionalities otherthan the carbonate or hydroxy groups.

Effects of this type can, by way of example, be achieved via addition,during the polycondensation, of compounds which bear other functionalgroups or functional elements; such as mercapto groups; primary,secondary or tertiary amino groups, ether groups, derivatives ofcarboxylic adds, derivatives of sulfonic acids, derivatives ofphosphonic acids, siiane groups, siloxane groups, aryl radicals, orlong-chain alkyl radicals, besides hydroxy groups, carbonate groups orcarbamoyl groups. Examples of compounds which may be used formodification by means of carbamate groups are ethanolamine,propanolamine, isopropanolamine, 2-(butylamino)ethanol,2-(cyclohexylamino)ethanol, 2-amino-1-butanol, 2-(2′-aminoethoxy)ethanolor higher alkoxylation products of ammonia, 4-hydroxypiperidine,1-hydroxyethylpiperazine, diethanolamine, dipropanolamine,diisopropanolamine, tris(hydroxymethyl)aminomethane,tris(hydroxyethyl)aminomethane, ethylenediamine, propylenediamine,hexamethylenediamine or isophoronediamine.

An example of a compound which can be used for modification withmercapto groups is mercaptoethanol. By way of example, tertian/aminogroups can be produced via incorporation of N-methyldiethanolamine,N-methyldipropanolamine or N,N-dimethylethanolamine. By way of example,ether groups may be generated via co-condensation of dihydric or higherpolyhydric polyetherols. Long-chain alkyl radicals can be introduced viareaction with long-chain alkanediols, and reaction with alkyl or aryldiisocyanates generates polycarbonates having alkyl, aryl, and urethanegroups, or urea groups.

Ester groups can be produced via addition of dicarboxylic acids,tricarboxylic acids, for example dimethyl terephthalate, ortricarboxylic esters.

Subsequent functionalization can be achieved by using an additional stepof the process (step c)) to react the resultant highly functional highlybranched, or highly functional hyperbranched polycarbonate with asuitable functionalizing reagent which can react with the OH and/orcarbonate groups or carbamoyl groups of the polycarbonate.

By way of example, highly functional highly branched, or highlyfunctional hyperbranched polycarbonates comprising hydroxy groups can bemodified via addition of molecules comprising acid groups or isocyanategroups. By way of example, polycarbonates comprising acid groups can beobtained via reaction with compounds comprising anhydride groups.

Highly functional polycarbonates comprising hydroxy groups may moreoveralso be converted into highly functional polycarbonate polyether polyolsvia reaction with alkylene oxides, e.g. ethylene oxide, propylene oxide,or butylene oxide.

A great advantage of the process is its cost-effectiveness. Both thereaction to give a condensate (K) or polycondensate (P) and also thereaction of (K) or (P) to give polycarbonates with other functionalgroups or elements can take place in one reactor, this beingadvantageous technically and in terms of cost-effectiveness.

The inventive molding compositions may comprise, as component B2), atleast one hyperbranched polyester of A_(x)B_(y) type, where

x is at least 1.1, preferably at least 1.3, in particular at least 2

y is at least 2.1, preferably at least 2.5, in particular at least 3.

Use may also be made of mixtures as units A and/or B, of course.

An A_(x)B_(y)-type polyester is a condensate composed or an x-functionalmolecule A and a y-functional molecule B. By way of example, mention maybe made of a polyester composed of adipic acid as molecule A (x=2) andglycerol as molecule B (y=3).

For the purposes of this invention, hyperbranched polyesters B2) arenon-crosslinked macromolecules having hydroxy groups and carboxy groups,these having both structural and molecular non-uniformity. Theirstructure may firstly be based on a central molecule in the same way asdendrimers, but with non-uniform chain length of the branches. Secondly,they may also have a linear structure with functional pendant groups, orelse they may combine the two extremes, having linear and branchedmolecular portions. See also P. J. Flory, J. Am. Chem. Soc. 1952, 74,2718, and H. Frey et al., Chem. Eur. J. 2000, 6, no. 14, 2499 for thedefinition of dendrimeric and hyperbranched polymers.

“Hyperbranched” in the context of the present invention means that thedegree of branching (DB), i.e. the average number of dendritic linkagesplus the average number of end groups per molecule, is from 10 to 99.9%,preferably from 20 to 99%, particularly preferably from 20 to 95%.“Dendrimeric” in the context of the present invention means that thedegree of branching is from 99.9 to 100%. See H. Frey et al., ActaPolym. 1997, 48, 30, and the formula given above under B1) for thedefinition of “degree of branching”.

Component B2) preferably has an M_(n) of from 300 to 30 000 g/mol, inparticular from 400 to 25 000 g/mol, and very particularly from 500 to20 000 g/mol, determined by means of GPC, PMMA standard,dimethylacetamide eluent.

B2) preferably has an OH number of from 0 to 600 mg KOH/g of polyester,preferably from 1 to 500 mg KOH/g of polyester, in particular from 20 to500 mg KOH/g of polyester to DIN 53240, and preferably a COOH number offrom 0 to 600 mg KOH/g of polyester, preferably from 1 to 500 mg KOH/gof polyester, and in particular from 2 to 500 mg KOH/g of polyester.

The T_(g) is preferably from −50° C. to 140° C., and in particular from−50 to 100° C. (by means of DSC, to DIN 53765).

Preference is particularly given to those components B2) in which atleast one OH or COOH number is greater than 0, preferably greater than0.1, and in particular greater than 0.5.

The inventive component B2) is in particular obtainable via theprocesses described below, specifically by reacting

-   (a) one or more dicarboxylic acids or one or more derivatives of the    same with one or more at least trihydric alcohols    or-   (b) one or more tricarboxylic acids or higher polycarboxylic acids    or one or more derivatives of the same with one or more diols    in the presence of a solvent and optionally in the presence of an    inorganic, organometallic, or low-molecular-weight organic catalyst,    or of an enzyme. The reaction in solvent is the preferred    preparation method.

For the purposes of the present invention, highly functionalhyperbranched polyesters B2) have molecular and structuralnon-uniformity. Their molecular non-uniformity distinguishes them fromdendrimers, and they can therefore be prepared at considerably lowercost.

Among the dicarboxylic acids which can be reacted according to variant(a) are, by way of example, oxalic acid, malonic acid, succinic acid,glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid,sebacic acid, undecane-α,ω-dicarboxylic acid, dodecane-α,ω-dicarboxylicacid, cis- and trans-cyclohexane-1,2-dicarboxylic acid, cis- andtrans-cyclohexane-1,3-dicarboxylic acid, cis- andtrans-cyclohexane-1,4-di-carboxylic acid, cis- andtrans-cyclopentane-1,2-dicarboxylic acid, and cis- andtrans-cyclopentane-1,3-dicarboxylic acid,

where the abovementioned dicarboxylic acids may have substitution by oneor more radicals selected from

C₁-C₁₀-alkyl groups, such as methyl, ethyl, n-propyl, isopropyl,n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl,sec-pentyl, neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl, isohexyl,sec-hexyl, n-heptyl, isoheptyl, n-octyl, 2-ethylhexyl, n-nonyl, andn-decyl,C₃-C₁₂-cycloalkyl groups, such as cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl,cycloundecyl, and cyclododecyl;preference is given to cyclopentyl, cyclohexyl, and cycloheptyl;alkylene groups, such as methylene or ethylidene, orC₆-C₁₄-aryl groups, such as phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl,2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl,4-phenanthryl, and 9-phenanthryl, preferably phenyl, 1-naphthyl, and2-naphthyl, particularly preferably phenyl.

Examples which may be mentioned as representatives of substituteddicarboxylic acids are: 2-methylmalonic acid, 2-ethylmalonic acid,2-phenylmalonic acid, 2-methylsuccinic acid, 2-ethylsuccinic acid,2-phenylsuccinic acid, itaconic acid, 3,3-dimethylglutaric acid.

Among the dicarboxylic acids which can be reacted according to variant(a) are also ethylenically unsaturated acids, such as maleic add andfumaric acid, and aromatic dicarboxylic acids, such as phthalic acid,isophthalic acid or terephthalic acid.

It is also possible to use mixtures of two or more of the abovementionedrepresentative compounds.

The dicarboxylic acids may either be used as they stand or be used inthe form of derivatives.

Derivatives are preferably

-   -   the relevant anhydrides in monomeric or else polymeric form,    -   mono- or dialkyl esters, preferably mono- or dimethyl esters, or        the corresponding mono- or diethyl esters, or else the mono- and        dialkyl esters derived from higher alcohols, such as n-propanol,        isopropanol, n-butanol, isobutanol, tert-butanol, n-pentanol,        n-hexanol,    -   and also mono- and divinyl esters; and    -   mixed esters, preferably methyl ethyl esters.

In the preferred preparation process it is also possible to use amixture composed of a dicarboxylic acid and one or more of itsderivatives. Equally, it is possible to use a mixture of two or moredifferent derivatives of one or more dicarboxylic acids.

It is particularly preferable to use succinic acid, glutaric acid,adipic acid, phthalic acid, isophthalic acid, terephthalic acid, or themono- or dimethyl esters thereof. It is very particularly preferable touse adipic acid.

Examples of at least trihydric alcohols which may be reacted are:glycerol, butane-1,2,4-triol, n-pentane-1,2,5-triol,n-pentane-1,3,5-triol, n-hexane-1,2,6-triol, n-hexane-1,3,6-triol,trimethylolbutane, trimethylolpropane or ditrimethylolpropane,trimethylolethane, pentaerythritol or dipentaerythritol; sugar alcohols,such as mesoerythritol, threitol, sorbitol, mannitol, or mixtures of theabove at least trihydric alcohols. It is preferable to use glycerol,trimethylolpropane, trimethylolethane, and pentaerythritol.

Examples of tricarboxylic acids or polycarboxylic acids which can bereacted according to variant (b) are benzene-1,2,4-tricarboxylic acid,benzene-1,3,5-tricarboxylic acid, benzene-1,2,4,5-tetracarboxylic acid,and mellitic acid.

Tricarboxylic acids or polycarboxylic acids may be used in the inventivereaction either as they stand or else in the form of derivatives.

Derivatives are preferably

-   -   the relevant anhydrides in monomeric or else polymeric form,    -   mono-, di-, or trialkyl esters, preferably mono-, di-, or        trimethyl esters, or the corresponding mono-, di-, or triethyl        esters, or else the mono-, di-, and triesters derived from        higher alcohols, such as n-propanol, isopropanol, n-butanol,        isobutanol, tert-butanol, n-pentanol, n-hexanol, or else mono-,        di-, or trivinyl esters    -   and mixed methyl ethyl esters.

For the purposes of the present invention, it is also possible to use amixture composed of a tri- or polycarboxylic acid and one or more of itsderivatives. For the purposes of the present invention it is likewisepossible to use a mixture of two or more different derivatives of one ormore tri- or polycarboxylic acids, in order to obtain component B2).

Examples of diols used for variant (b) of the present invention areethylene glycol, propane-1,2-diol, propane-1,3-diol, butane-1,2-diol,butane-1,3-diol, butane-1,4-diol, butane-2,3-diol, pentane-1,2-diol,pentane-1,3-diol, pentane-1,4-diol, pentane-1,5-diol, pentane-2,3-diol,pentane-2,4-diol, hexane-1,2-diol, hexane-1,3-diol, hexane-1,4-diol,hexane-1,5-diol, hexane-1,6-diol, hexane-2,5-diol, heptane-1,2-diol,1,7-heptanediol, 1,8-octanediol, 1,2-octanediol, 1,9-nonanediol,1,10-decanediol, 1,2-decanediol, 1,12-dodecanediol, 1,2-dodecanediol,1,5-hexadiene-3,4-diol, cyclopentanediols, cyclohexanediols, inositoland derivatives, (2)-methylpentane-2,4-diol,2,4-dimethylpentane-2,4-diol; 2-ethylhexane-1,3-diol,2,5-dimethylhexane-2,5-diol, 2,2,4-trimethylpentane-1,3-diol, pinacol,diethylene glycol, triethylene glycol, dipropylene glycol, tripropyleneglycol, polyethylene glycols HO(CH₂CH₂O)_(n)—H or polypropylene glycolsHO(CH[CH₃]CH₂O)_(n)—H or mixtures of two or more representativecompounds of the above compounds, where n is a whole number and n=4.One, or else both, hydroxy groups here in the abovementioned diols mayalso be replaced by SH groups. Preference is given to ethylene glycol,propane-1,2-diol, and diethylene glycol, triethylene glycol, dipropyleneglycol, and tripropylene glycol.

The molar ratio of the molecules A to molecules B in the A_(x)B_(y)polyester in the variants (a) and (b) is from 4:1 to 1:4, in particularfrom 2:1 to 1:2.

The at least trihydric alcohols reacted according to variant (a) of theprocess may have hydroxy groups of which all have identical reactivity.Preference is also given here to at least trihydric alcohols whose OHgroups initially have identical reactivity, but where reaction with atleast one acid group can induce a fall-off in reactivity of theremaining OH groups as a result of steric or electronic effects. By wayof example, this applies when trimethylolpropane or pentaerythritol isused.

However, the at least trihydric alcohols reacted according to variant(a) may also have hydroxy groups having at least two different chemicalreactivities.

The different reactivity of the functional groups here may derive eitherfrom chemical causes (e.g. primary/secondary/tertiary OH group) or fromsteric causes.

By way of example, the triol may comprise a triol which has primary andsecondary hydroxy groups, a preferred example being glycerol.

When the inventive reaction is carried out according to variant (a), itis preferable to operate in the absence of diols and of monohydricalcohols.

When the inventive reaction is carried out according to variant (b), itis preferable to operate in the absence of mono- or dicarboxylic acids.

The inventive process is carried out in the presence of a solvent. Byway of example, hydrocarbons are suitable, such as paraffins oraromatics. Particularly suitable paraffins are n-heptane andcyclohexane. Particularly suitable aromatics are toluene, ortho-xylene,meta-xylene, para-xylene, xylene in the form of an isomer mixture,ethylbenzene, chlorobenzene, and ortho- and meta-dichlorobenzene. Othersolvents very particularly suitable in the absence of acidic catalystsare: ethers, such as dioxane or tetrahydrofuran, and ketones, such asmethyl ethyl ketone and methyl isobutyl ketone.

According to the invention, the amount of solvent added is at least 0.1%by weight, based on the weight of the starting materials used and to bereacted, preferably at least 1% by weight, and particularly preferablyat least 10% by weight. It is also possible to use excesses of solvent,based on the weight of starting materials used and to be reacted, e.g.from 1.01 to 10 times the amount. Solvent amounts of more than 100 timesthe weight of the starting materials used and lobe reacted are notadvantageous, because the reaction rate decreases markedly at markedlylower concentrations of the reactants, giving uneconomically longreaction times.

To carry out the process preferred according to the invention,operations may be carried out in the presence of a dehydrating agent asadditive, added at the start of the reaction. Suitable examples aremolecular sieves, in particular 4 Å molecular sieve, MgSO₄, and Na₂SO₄.During the reaction it is also possible to add further dehydrating agentor to replace dehydrating agent by fresh dehydrating agent. During thereaction it is also possible to remove the water or alcohol formed bydistillation and, for example, to use a water trap.

The process may be carried out in the absence of acidic catalysts. It ispreferable to operate in the presence of an acidic inorganic,organometallic, or organic catalyst, or a mixture composed of two ormore acidic inorganic, organometallic, or organic catalysts.

For the purposes of the present invention, examples of acidic inorganiccatalysts are sulfuric acid, phosphoric acid, phosphonic acid,hypophosphorous acid, aluminum sulfate hydrate, alum, acidic silica gel(pH=6, in particular =5), and acidic aluminum oxide. Examples of othercompounds which can be used as acidic inorganic catalysts are aluminumcompounds of the general formula Al(OR)₃ and titanates of the generalformula Ti(OR)₄, where each of the radicals R may be identical ordifferent and is selected independently of the others from

C₁-C₁₀-alkyl radicals, such as methyl, ethyl, n-propyl, isopropyl,n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl,sec-pentyl, neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl, isohexyl,sec-hexyl, n-heptyl, isoheptyl, n-octyl, 2-ethylhexyl, n-nonyl, andn-decyl,C₃-C₁₂-cycloalkyl radicals, such as cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl,cyclodecyl, cycloundecyl, and cyclododecyl; preference is given tocyclopentyl, cyclohexyl, and cycloheptyl.

Each of the radicals R in Al(OR)₃ or Ti(OR)₄ is preferably identical andselected from isopropyl or 2-ethylhexyl.

Examples of preferred acidic organometallic catalysts are selected fromdialkyltin oxides R₂SnO, where R is defined as above. A particularlypreferred representative compound for acidic organometallic catalysts isdi-n-butyltin oxide, which is commercially available as “oxo-tin”, ordi-n-butyltin dilaurate.

Preferred acidic organic catalysts are acidic organic compounds having,by way of example, phosphate groups, sulfonic acid groups, sulfategroups, or phosphonic acid groups. Particular preference is given tosulfonic acids, such as para-toluenesulfonic acid. Acidic ion exchangersmay also be used as acidic organic catalysts, e.g. polystyrene resinscomprising sulfonic acid groups and crosslinked with about 2 mol % ofdivinylbenzene.

It is also possible to use combinations of two or more of theabovementioned catalysts. It is also possible to use an immobilized formof those organic or organometallic, or else inorganic catalysts whichtake the form of discrete molecules.

If the intention is to use acidic inorganic, organometallic, or organiccatalysts, according to the invention the amount used is from 0.1 to 10%by weight, preferably from 0.2 to 2% by weight, of catalyst.

The inventive process is carried out under inert gas, e.g. under carbondioxide, nitrogen, or a noble gas, among which mention may particularlybe made of argon.

The inventive process is carried out at temperatures of from 60 to 200°C. It is preferable to operate at temperatures, of from 130 to 180° C.,in particular up to 150° C., or below that temperature. Maximumtemperatures up to 145° C. are particularly preferred, and temperaturesup to 135° C. are very particularly preferred.

The pressure conditions for the inventive process are not critical perse. It is possible to operate at markedly reduced pressure, e.g. at from10 to 500 mbar. The inventive process may also be carried out atpressures above 500 mbar. A reaction at atmospheric pressure ispreferred for reasons of simplicity; however, conduct at slightlyincreased pressure is also possible, e.g. up to 1200 mbar. It is alsopossible to operate at markedly increased pressure, e.g. at pressures upto 10 bar. Reaction at atmospheric pressure is preferred.

The reaction time for the inventive process is usually from 10 minutesto 25 hours, preferably from 30 minutes to 10 hours, and particularlypreferably from one to 8 hours.

Once the reaction has ended, the highly functional hyperbranchedpolyesters can easily be, isolated, e.g. by removing the catalyst byfiltration and concentrating the mixture, the concentration process hereusually being carried out at reduced pressure. Other work-Up methodswith good suitability are precipitation after addition of water,followed by washing and drying.

Component B2) can also be prepared in the presence of enzymes ordecomposition products of enzymes (according to DE-A 101 63163). For thepurposes of the present invention, the term acidic organic catalystsdoes not include the dicarboxylic acids reacted according to theinvention.

It is preferable to use lipases or esterases. Lipases and esterases withgood suitability are Candida cylindracea, Candida lipolytica, Candidarugosa, Candida antarctica, Candida utilis, Chromobacterium viscosum,Geotrichum viscosum, Geotrichum candidum, Mucor javanicus, Mucor mihei,pig pancreas, pseudomonas spp., pseudomonas fluorescens, Pseudomonascepacia, Rhizopus arrhizus, Rhizopus delemar, Rhizopus niveus, Rhizopusoryzae, Aspergillus niger, Penicillium roquefortii, Penicilliumcamembertii, or esterase from Bacillus spp. and Bacillusthermoglucosidasius. Candida antarctica lipase B is particularlypreferred. The enzymes listed are commercially available, for examplefrom Novozymes Biotech Inc., Denmark.

The enzyme it preferably used in immobilized form, for example on silicagel or Lewatit®. The processes for immobilizing enzymes are know per se,e.g. from Kurt Faber, “Biotransformations in organic-chemistry”, 3rdedition 1997, Springer Verlag, Chapter 3.2 “immobilization” pp. 345-356.Immobilized enzymes are commercially available, for example fromNovozymes Biotech Inc., Denmark.

The amount of immobilized enzyme used is from 0.1 to 20% by weight, inparticular from 10 to 15% by weight, based on the total weight of thestarting materials used and to be reacted.

The inventive process is carried out at temperatures above 60° C. It ispreferable to operate at temperatures of 100° C. or below thattemperature. Preference is given to temperatures up to 80° C., veryparticular preference is given to temperatures of from 62 to 75° C., andstill more preference is given to temperatures of from 65 to 75° C.

The inventive process is carried out in the presence of a solvent.Examples of suitable compounds are hydrocarbons, such as paraffins oraromatics. Particularly suitable paraffins are n-heptane andcyclohexane. Particularly suitable aromatics are toluene, ortho-xylene,meta-xylene, para-xylene, xylene in the form of an isomer mixture,ethylbenzene, chlorobenzene and ortho- and meta-dichlorobenzene. Othervery particularly suitable solvents are: ethers, such as dioxane ortetrahydrofuran, and ketones, such as methyl ethyl ketone and methylisobutyl ketone.

The amount of solvent added is at least 5 parts by weight, based on theweight of the starting materials used and to be reacted, preferably atleast 50 parts by weight, and particularly preferably at least 100 partsby weight. Amounts of more than 10 000 parts by weight of solvent areundesirable, because the reaction rate decreases markedly at markedlylower concentrations, giving uneconomically long reaction times.

The inventive process is carried out at pressures above 500 mbar.Preference is given to the reaction at atmospheric pressure or slightlyincreased pressure, for example at up to 1200 mbar. It is also possibleto operate under markedly increased pressure; for example at pressuresup to 10 bar. The reaction at atmospheric pressure is preferred.

The reaction time for the inventive process is usually from 4 hours to 6days, preferably from 5 hours to 5 days, and particularly preferablyfrom 8 hours to 4 days.

Once the reaction has ended, the highly functional hyperbranchedpolyesters can be isolated, e.g. by removing the enzyme by filtrationand concentrating the mixture, this concentration process usually beingcarried out at reduced pressure. Other work-up methods with goodsuitability are precipitation after addition of water, followed bywashing and drying.

The highly functional, hyperbranched polyesters obtainable by theinventive process feature particularly low contents of discolored andresinified material. For the definition of hyperbranched polymers, seealso: P. J. Flory, J. Am. Chem. Soc. 1952, 74, 2718, and A. Sunder etal., Chem. Eur. J. 2000, 6, no. 1, 1-8. However, in the context of thepresent invention, “highly functional hyperbranched” means that thedegree of branching, i.e. the average number of dendritic linkages plusthe average number of end groups per molecule, is from 10 to 99.9%,preferably from 20 to 99%, particularly preferably from 30 to 90% (seein this connection H. Frey et al. Acta Polym. 1997, 48, 30).

The inventive polyesters have a molar mass M_(w) of from 500 to 50 000g/mol, preferably from 1000 to 20 000 g/mol, particularly preferablyfrom 1000 to 19 000 g/mol. The polydispersity is from 1.2 to 50,preferably from 1.4 to 40, particularly preferably from 1.5 to 30, andvery particularly preferably from 1.5 to 10. They are usually verysoluble, i.e. clear solutions can be prepared using up to 50,% byweight, in some cases even up to 80% by weight, of the inventivepolyesters in tetrahydrofuran (THF), n-butyl acetate, ethanol, andnumerous other solvents, with no gel particles detectable by the nakedeye.

The inventive highly functional hyperbranched polyesters arecarboxy-terminated, carboxy- and hydroxy-terminated, and preferablyhydroxy-terminated.

The ratios of the components B1):B2) are preferably from 1:20 to 20:1,in particular from 1:15 to 15:1, and very particularly from 1:5 to 5:1if a mixture of these is used.

The hyperbranched polycarbonates B1)/polyesters B2) used arenanoparticles. The size of the particles in the compounded material isfrom 20 to 500 nm, preferably from 50 to 300 nm.

Compounded materials of this type are available commercially, e.g. inthe form of Ultradur® high speed.

Fibrous dr particulate fillers C) that may be mentioned are carbonfibers, glass fibers, glass beads, amorphous silica, asbestos, calciumsilicate, calcium metasilicate, magnesium carbonate, kaolin, chalk,powdered quartz, mica, barium sulfate, and feldspar, the amounts used ofthese being from 10 to 60% by weight, in particular from 30 to 60% byweight, and very particularly preferably from 40 to 55% by weight.

Preferred fibrous fillers that may be mentioned are carbon fibers,aramid fibers, and potassium titanate fibers, particular preferencebeing given to glass fibers in the form of E glass. These can be used asrovings or as chopped glass, in the forms commercially available.

Particular preference is given to mixtures of glass fibers C) withcomponent B) in a ratio of from 1:100 to 1:2 and preferably from 1:10 to1:3.

The fibrous fillers can have been surface-treated in advance with asilane compound to improve compatibility with the thermoplastic.

Suitable silane compounds are those of the general formula(X—(CH₂)_(n))_(k)—Si—(O—C_(m)H_(2m+1))_(4-k)in which the definition of the substituents is as follows:

n is a whole number from 2 to 10, preferably from 3 to 4m is a whole number from 1 to 5, preferably from 1 to 2, andk is a whole number from 1 to 3, preferably 1.

Preferred silane compounds are aminopropyltrimethoxysilane,aminobutyltrimethoxysilane, aminopropyltriethoxysilane,aminobutyltriethoxysilane, and also the corresponding silanes whichcomprise a glycidyl group as substituent X.

The amounts generally used of the silane compounds for surface coating(based on D) are from 0.05 to 5% by weight, preferably from 0.5 to 1.5%by weight, and in particular from 0.8 to 1% by weight.

Acicular mineral fillers are also suitable.

For the purposes of the invention, acicular mineral fillers are amineral filler with pronounced acicular character. An example that Maybe mentioned is acicular wollastonite. The L/D (length to diameter)ratio of the mineral is preferably from 8:1 to 35:1, with preferencefrom 8:1 to 11:1. The mineral filler can, if appropriate, have beentreated in advance with the abovementioned silane compounds; however,this pretreatment is not essential.

Further fillers that may be mentioned are kaolin, calcined kaolin,wollastonite, talc, and chalk.

The inventive molding compositions can comprise, as component D), from 0to 20% by weight, in particular up to 15% by weight, of furtheradditives and processing aids.

The inventive molding compositions can comprise, as component D), from 0to 5% by weight, preferably from 0.05 to 3% by weight, and in particularfrom 0.1 to 2% by weight, of at least one ester or amide of saturated orunsaturated aliphatic carboxylic acids having from 10 to 40 carbonatoms, preferably from 16 to 22 carbon atoms, with saturated aliphaticalcohols or amines having from 2 to 40 carbon atoms, preferably from 2to 6 carbon atoms.

The carboxylic acids may be monobasic or dibasic. Examples which may bementioned are pelargonic acid, palmitic acid, lauric acid, margaricacid, dodecanedioic acid, behenic acid, and particularly preferablystearic acid, capric acid, and also montanic acid (a mixture of fattyacids having from 30 to 40 carbon atoms).

The aliphatic alcohols may be mono- to tetrahydric. Examples of alcoholsare n-butanol, n-octanol, stearyl alcohol, ethylene glycol, propyleneglycol, neopentyl glycol pentaerythritol, preference being given toglycerol and pentaerythritol.

The aliphatic amines may be mono-, di- or triamines. Examples of theseare stearylamine, ethylenediamine, propylenediamine,hexamethylenediamine, di(6-aminohexyl)amine, particular preference beinggiven to ethylenediamine and hexamethylenediamine. Correspondingly,preferred esters or amides are glyceryl distearate, glyceryltristearate, ethylenediamine distearate, glyceryl monopalmitate,glyceryl trilaurate, glyceryl monobehenate, and pentaerythrityltetrastearate.

It is also possible to use mixtures of various esters or amides, oresters with amides combined, the mixing ratio here being as desired.

Examples of amounts of further usual additives D) are up to 40% byweight, preferably up to 30% by weight, of elastomeric polymers (alsooften termed impact modifiers, elastomers, or rubbers).

These are very generally copolymers which have preferably been built upfrom at least two of the following monomers: ethylene, propylene,butadiene, isobutene, isoprene, chloroprene, vinyl acetate, styrene,acrylonitrile and acrylates and/or methacrylates having from 1 to 18carbon atoms in the alcohol component.

Polymers of this type are described, for example, in Houben-Weyl,Methoden der organischen Chemie, Vol. 14/1 (Georg-Thieme-Verlag,Stuttgart, Germany, 1961), pages 392-406, and in the monograph by C. B.Bucknall, “Toughened Plastics” (Applied Science Publishers, London, UK,1977).

Some preferred types of such elastomers are described below.

Preferred types of such elastomers are those known as ethylene-propylene(EPM) and ethylene-propylene-diene (EPDM) rubbers.

EPM rubbers generally have practically no residual double bonds, whereasEPDM rubbers may have from 1 to 20 double bonds per 100 carbon atoms.

Examples which may be mentioned of diene monomers for EPDM rubbers areconjugated dienes, such as isoprene and butadiene, non-conjugated dieneshaving from 5 to 25 carbon atoms, such as 1,4-pentadiene, 1,4-hexadiene,1,5-hexadiene, 2,5-dimethyl-1,5-hexadiene and 1,4-octadiene, cyclicdienes, such as cyclopentadiene, cyclohexadienes, cyclooctadienes anddicyclopentadiene, and also alkenylnorbornenes, such as5-ethylidene-2-norbornene, 5-butylidene-2-norbornene,2-methallyl-5-norbornene and 2-isopropenyl-5-norbornene, andtricyclodienes, such as 3-methyltricyclo[5.2.1.0^(2,6)]-3,8-decadiene,and mixtures of these. Preference is given to 1,5-hexadiene,5-ethylidenenorbornene and dicyclopentadiene. The diene content of theEPDM rubbers is preferably from 0.5 to 50% by weight, in particular from1 to 8% by weight, based on the total weight of the rubber.

EPM and EPDM rubbers may preferably also have been grafted with reactivecarboxylic acids or with derivatives of these. Examples of these whichmay be mentioned are acrylic acid, methacrylic acid and derivativesthereof, e.g. glycidyl (meth)acrylate, and also maleic anhydride.

Copolymers of ethylene with acrylic acid and/or methacrylic acid and/orwith the esters of these acids are another group of preferred rubbers.The rubbers may also comprise dicarboxylic acids, such as maleic acidand fumaric acid, or derivatives of these acids, e.g. esters andanhydrides, and/or monomers comprising epoxy groups. These monomerscomprising dicarboxylic acid derivatives or comprising epoxy groups arepreferably incorporated into the rubber by adding to the monomer mixturemonomers comprising dicarboxylic acid groups and/or epoxy groups andhaving the general formula I or II or III or IV

where R¹ to R⁹ are hydrogen or alkyl groups having from 1 to 6 carbonatoms, and m is a whole number from 0 to 20, g is a whole number from 0to 10 and p is a whole number from 0 to 5.

The radicals R¹ to R⁹ are preferably hydrogen, where m is 0 or 1 and gis 1. The corresponding compounds are maleic acid, fumaric acid, maleicanhydride, ally, glycidyl ether and vinyl glycidyl ether.

Preferred compounds of the formulae I, II and IV are maleic acid, maleicanhydride and (meth)acrylates comprising epoxy groups, such as glycidylacrylate and glycidyl methacrylate, and the esters with tertiaryalcohols, such as tert-butyl acrylate. Although the latter have no freecarboxy groups, their behavior approximates to that of the free acidsand they are therefore termed monomers with latent carboxy groups.

The copolymers are advantageously composed of from 50 to 98% by weightof ethylene, from 0.1 to 20% by weight of monomers comprising epoxygroups and/or methacrylic acid and/or monomers comprising anhydridegroups, the remaining amount being (meth)acrylates.

Particular preference is given to copolymers composed of

from 50 to 98% by weight, in particular from 55 to 95% by weight, ofethylene,

from 0.1 to 40% by weight, in particular from 0.3 to 20% by weight, ofglycidyl acrylate and/or glycidyl methacrylate, (meth)acrylic acidand/or maleic anhydride, and

from 1 to 45% by weight, in particular from 10 to 40% by weight, ofn-butyl acrylate and/or 2-ethylhexyl acrylate.

Other preferred (meth)acrylates are the methyl, ethyl, propyl, isobutyland tert-butyl esters.

Besides these, comonomers which may be used are vinyl esters and vinylethers.

The ethylene copolymers described above may be prepared by processesknown per se, preferably by random copolymerization at high pressure andelevated temperature. Appropriate processes are well known.

Other preferred elastomers are emulsion polymers whose preparation isdescribed, for example, by Blackley in the monograph “EmulsionPolymerization”. The emulsifiers and catalysts which can be used areknown per se.

In principle it is possible to use homogeneously structured elastomersor else those with a shell structure. The shell-type structure isdetermined by the sequence of addition of the individual monomers; themorphology of the polymers is also affected by this sequence ofaddition.

Monomers which may be mentioned here, merely in a representativecapacity, for the preparation of the rubber fraction of the elastomersare acrylates, such as n-butyl acrylate and 2-ethylhexyl acrylate,corresponding methacrylates, butadiene and isoprene, and also mixturesof these. These monomers may be copolymerized with other monomers, suchas styrene, acrylonitrile, vinyl ethers and with other acrylates ormethacrylates, such as methyl methacrylate, methyl acrylate, ethylacrylate or propyl acrylate.

The soft or rubber phase (with a glass transition temperature of below0° C.) of the elastomers may be the core, the outer envelope or anintermediate shell (in the case of elastomers whose structure has morethan two shells). Elastomers having more than one shell may also havetwo or more shells composed of a rubber phase.

If one or more hard components (with glass transition temperatures above20° C.) are involved, besides the rubber phase, in the structure of theelastomer, these are generally prepared by polymerizing, as principalmonomers, styrene, acrylonitrile, methacrylonitrile, α-methylstyrene,p-methylstyrene, or acrylates or methacrylates, such as methyl acrylate,ethyl acrylate or methyl methacrylate. Besides these, it is alsopossible to use relatively small proportions of other comonomers.

It has proven advantageous in some cases to use emulsion polymers whichhave reactive groups at their surfaces. Examples of groups of this typeare epoxy, carboxy, latent carboxy, amino and amide groups, and alsofunctional groups which may be introduced by concomitant use of monomersof the general formula

where the substituents can be as follows:R¹⁰ is hydrogen or C₁-C₄-alkyl,R¹¹ is hydrogen or C₁-C₈-alkyl or aryl, in particular phenyl,R¹² is hydrogen, C₁-C₁₀-alkyl, C₆-C₁₂-aryl or —OR¹³R¹³ is C₁-C₈-alkyl or C₆-C₁₂-aryl, optionally substituted by O— orN-Containing groups,X is a chemical bond or C₁-C₁₀-alkylene or C₆-C₁₂-arylene, or

Y is O—Z or NH—Z, andZ is C₁-C₁₀-alkylene or C₆-C₁₂-arylene.

The graft monomers described in EP-A 208 187 are also suitable forintroducing reactive groups at the surface.

Other examples which may be mentioned are acrylamide, methacrylamide andsubstituted acrylates or methacrylates, such as (N-tert-butylamino)ethylmethacrylate, (N,N-dimethylamino)ethyl acrylate,(N,N-dimethylamino)methyl acrylate and (N,N-diethylamino)ethyl acrylate.

The particles of the rubber phase may also have been crosslinked.Examples of crosslinking monomers are 1,3-butadiene, divinylbenzene,diallyl phthalate and dihydrodicyclopentadienyl acrylate, and also thecompounds described in EP-A 50 265.

It is also possible to use the monomers known as graft-linking monomers,i.e. monomers having two or more polymerizable double bonds which reactat different rates during the polymerization. Preference is given to theuse of compounds of this type in which at least one reactive grouppolymerizes at about the same rate as the other monomers, while theother reactive group (or reactive groups), for example, polymerize(s)significantly more slowly. The different polymerization rates give riseto a certain proportion of double-bond unsaturation in the rubber. Ifanother phase is then grafted onto a rubber of this type, at least someof the double bonds present in the rubber react with the graft monomersto form chemical bonds, i.e. the phase grafted on has at least somedegree of chemical bonding to the graft base.

Examples of graft-linking monomers of this type are monomers comprisingallyl groups, in particular allyl esters of ethylenically unsaturatedcarboxylic acids, for example allyl acrylate, allyl methacrylate,diallyl maleate, diallyl fumarate and diallyl itaconate, and thecorresponding monoallyl compounds of these dicarboxylic acids. Besidesthese there is a wide variety of other suitable graft-linking monomers.For further details reference may be made here, for example, to U.S.Pat. No. 4,148,846.

The proportion of these crosslinking monomers in the impact-modifyingpolymer is generally up to 5% by weight, preferably not more than 3% byweight, based on the impact-modifying polymer.

Some preferred emulsion polymers are listed below. Mention may first bemade here of graft polymers with a core and with at least one outershell, and having the following structure:

Type Monomers for the core Monomers for the envelope I 1,3-butadiene,isoprene, n-butyl styrene, acrylonitrile, methyl acrylate, ethylhexylacrylate, methacrylate or a mixture of these II as I, but withconcomitant use of as I crosslinking agents III as I or II n-butylacrylate, ethyl acrylate, methyl acrylate, 1,3-butadiene, isoprene,ethylhexyl acrylate IV as I or II as I or III, but with concomitant useof monomers having reactive groups, as described herein V styrene,acrylonitrile, methyl first envelope composed of methacrylate, or amixture of monomers as described under I these and II for the core,second envelope as described under I or IV for the envelope

These graft polymers, in particular ABS polymers and/or ASA polymers,are preferably used in amounts of up to 40% by weight for theimpact-modification of PBT, if appropriate in a mixture with up to 40%by weight of polyethylene terephthalate. Blend products of this type areobtainable with the trademark Ultradur®S (previously Ultrablend®S fromBASF AG).

Instead of graft polymers whose structure has more than one shell, it isalso possible to use homogeneous, i.e. single-shell, elastomers composedof 1,3-butadiene, isoprene and n-butyl acrylate or of copolymers ofthese. These products, too, may be prepared by concomitant use ofcrosslinking monomers or of monomers having reactive groups.

Examples of preferred emulsion polymers are n-butylacrylate-(meth)acrylic acid copolymers, n-butyl acrylate-glycidylacrylate or n-butyl acrylate-glycidyl methacrylate copolymers, graftpolymers with an inner core composed of n-butyl acrylate or based onbutadiene and with an outer envelope composed of the abovementionedcopolymers, and copolymers of ethylene with comonomers which supplyreactive groups.

The elastomers described may also be prepared by other conventionalprocesses, e.g. by suspension polymerization.

Preference is also given to silicone rubbers, as described in DE-A 37 25576, EP-A 235 690, DE-A 38 00 603 and EP-A 319 290.

It is, of course, also possible to use mixtures of the types of rubberlisted above.

As component D), the thermoplastic molding compositions of the inventionmay comprise the usual processing aids, such as stabilizers, oxidationretarders, agents to counteract decomposition due to heat anddecomposition due to ultraviolet light, lubricants and mold-releaseagents, colorants, such as dyes and pigments, nucleating agents,plasticizers, etc.

Examples which may be mentioned of oxidation retarders and heatstabilizers are sterically hindered phenols and/or phosphites,hydroquinones, aromatic secondary amines, such as diphenylamines,various substituted members of these groups, and mixtures of these inconcentrations of up to 1% by weight, based on the weight of thethermoplastic molding compositions.

UV stabilizers which may be mentioned, and are generally used in amountsof up to 2% by weight, based on the molding composition, are varioussubstituted resorcinols, salicylates, benzotriazoles, and benzophenones.

Colorants which may be added are inorganic pigments, such as titaniumdioxide; ultramarine blue, iron oxide, and carbon black, and alsoorganic pigments, such as phthalocyanines, quinacridones and perylenes,and also dyes, such as nigrosine and anthraquinones.

Nucleating agents which may be used are sodium phenylphosphinate,alumina, silica, and preferably talc.

Other lubricants and mold-release agents are usually used in amounts ofup to 1% by weight. Preference is given to long-chain fatty acids (e.g.stearic acid or behenic acid), salts of these (e.g. calcium stearate orzinc stearate) or montan waxes (mixtures of straight-chain saturatedcarboxylic acids having chain lengths of from 28 to 32 carbon atoms), orcalcium montanate or sodium montanate, or low-molecular-weightpolyethylene waxes or low-molecular-weight polypropylene waxes.

Examples of plasticizers which may be mentioned are dioctyl phthalates,dibenzyl phthalates, butyl benzyl phthalates, hydrocarbon oils andN-(n-butyl)benzenesulfonamide.

The inventive molding compositions may also comprise from 0 to 2% byweight of fluorine-containing ethylene polymers. These are polymers ofethylene with a fluorine content of from 55 to 76% by weight, preferablyfrom 70 to 76% by weight.

Examples of these are polytetrafluoroethylene (PTFE),tetrafluoroethylene-hexafluoropropylene copolymers andtetrafluoroethylene copolymers with relatively small proportions(generally up to 50% by weight) of copolymerizable ethylenicallyunsaturated monomers. These are described, for example, by Schildknechtin “Vinyl and Related Polymers”, Wiley-Verlag, 1952, pages 484-494 andby Wall in “Fluoropolymers” (Wiley Interscience, 1972).

These fluorine-containing ethylene polymers have homogeneousdistribution in the molding compositions and preferably have a particlesize d₅₀ (numeric average) in the range from 0.05 to 10 μm, inparticular from 0.1 to 5 μm. These small particle sizes can particularlypreferably be achieved by, the use of aqueous dispersions offluorine-containing ethylene polymers and incorporation of these into apolyester melt.

The inventive thermoplastic molding compositions may be prepared bymethods known per se, by mixing the starting components in conventionalmixing apparatus, such as screw extruderS, Brabender mixers or Banburymixers, and then extruding them. The extrudate may be cooled andcomminuted. It is also possible to premix individual components and thento add the remaining starting materials individually and/or likewise ina mixture. The mixing temperatures are generally from 230 to 290° C. Inone preferred variant of the premixing of the components, PET pellets orchips are mixed in advance with one another in for example, a tumblingmixer, and then processed by means of the gas- and/or water-injectionprocess. IGP/WI processes can be used separately or else, incombination.

IGP/WI processes are known as fluid-injection processes and include thefollowing general process features:

When the thermoplastic melt is in the (blow) mold, N₂/compressed air isintroduced at RT and at from 40 to 50 bar by way of a separate sectionof pipe (injector with supply line). On opening of the gas valve, wateris almost simultaneously passed under pressure (from 60 to 70 bar at RT)into the mold with an interval of about 2 seconds.

The gas is consequently compressed and the melt is pressed onto theexternal walls of the mold. The water remains in the mold for from 3 to5 seconds. A pressure reduction is then undertaken until the mold can beopened.

According to another preferred mode of operation, components B) and C),and also, if appropriate, D) can be mixed with a prepolymer, andcompounded and pelletized. The resultant pellets are then solid-phasecondensed continuously or batchwise under inert gas at a temperaturebelow the melting point of component A) until the desired viscosity hasbeen reached.

The inventive thermoplastic PET molding compositions and, respectively,PET blends feature good flowability and simultaneously improvedprocessing behavior. They also have a good and uniform surface at highfiller and permit coating with (powder) coatings.

These molding compositions are suitable for the production of liquid- orgas-conducting pipes, motor vehicle parts, kitchen elements, coatedmoldings, chair legs, table legs, exterior mirrors for cars and heavygoods vehicles, attachment systems for such mirrors, roof railings,stove handles, gas pipes, or gas lines.

EXAMPLES Component A/1

Polyethylene terephthalate with a viscosity number VN of . . . ml/g (VNmeasured in 0.5% strength by weight solution composed ofphenol/o-dichlorobenzene), 1:1 mixture at 25° C.

Component A/2

Polybutylene terephthalate with a viscosity number of 130 ml/g and witha carboxy end group content of 25 meq/kg (VN measured in 0.5% strengthby weight solution composed of phenol/o-dichlorobenzene, 1:1 mixture at25° C. to ISO 1628), comprising 0.65% by weight, based on A/2, ofpentaerythritol tetrastearate (component D1).

Preparation Specification for Polycarbonates B1

General Operating Specification:

As shown in table 1, equimolar amounts of the polyhydric alcohol anddiethyl carbonate were mixed in a three-necked flask equipped withstirrer, reflux condenser, and internal thermometer, and 250 ppm ofcatalyst (based on the amount of alcohol) were added. The mixture wasthen heated with stirring to 100° C., and in the experiment indicatedby * to 140° C., and stirred for 2 h at this temperature. The onset ofevaporative cooling caused by the monoalcohol liberated reduced thetemperature of the reaction mixture here as the reaction proceeded. Thereflux condenser was now replaced by an inclined condenser, ethanol wasremoved by distillation, and the temperature of the reaction mixture wasincreased slowly to 160° C.

The ethanol removed by distillation was collected in a cooledround-bottomed flask, and weighed, and the conversion was thusdetermined as a percentage based on the complete conversiontheoretically possible (see table 1).

The reaction products were then analyzed by gel permeationchromatography, the eluent being dimethylacetamide and the standardbeing polymethyl methacrylate (PMMA).

TABLE 1 Amount of eth- anol distillate, Molecular OH based on com-weight Visc. number Alco- plete conversion M_(w) 23° C. [mg hol Catalyst[mol %] M_(n) [mPas] KOH/g] B TMP × K₂CO₃ 70 2100 7200 461 1.2 PO 1500TMP = Trimethylolpropane PO = propylene oxide

Component C

Glass fibers with average thickness of 10 μm (epoxysilanized size)

Component D/2

25% strength carbon black masterbatch in component A/2

Components A) to D) were blended at from 250 to 260° C. in a twin-screwextruder and extruded into a water bath. After pelletization and drying,test specimens were injection-molded.

The pellets were injection-molded to give dumbbell specimens to ISO527-2 and a tensile test was carried out. Impact resistance to ISO 179-2was also determined, as also were viscosity (solvent for PBT to DIN53728: phenol/1,2-dichlorobenzene (1:1) ISO 1628), MVR (ISO 1133), andalso flow behavior.

DSC analysis was carried out to ISO 11357 (20 K steps), and heatdistortion temperature (HDT) was determined to ISO 75. A and B, anddensity was determined to ISO 11833.

Spiral test: Flow spiral of thickness 2 mm (T7 mold) for determinationof flow path length in cm.

Table 2 shows the inventive constitutions and the test results.

TABLE 2 Constitution Exam- [% by weight] ple 1 comp 1 A/1 26.80 27.00A/2 14.60 14.40 B — 0.60 C 50.00 50.00 D/1 0.60 — D/2 8.00 8.00 MVR250°/10 kg cm³/10′ 26 44 DSC analysis TM1/TSP1 ° C. 218.5/243.5217.7/243.3 1st heating H J/g 20 20.798 procedure TM2/TSP2 ° C.210.5/225   211.8 2nd heating H J/g 11 8.436 procedure TKB/Tko~ ° C. 188173 TKM/TKP ° C. 170.9 154.9 HWB ° C. 11 13.3 Tests unit MW Density MWg/cm³ 1.7602 1.7642 ISO 179/1eU impact   23° C. kJ/m² 59.3 53.7 test ISO179/1eU impact −30° C. kJ/m² 60.3 55.4 test ISO 179/1eA impact   23° C.kJ/m² 9.34 9.9 test ISO 75° HDT ° C. 184.8 199.7 ISO 75B HDT ° C. 219.1220.5 Tensile test Modulus of MPa 17 246 16 591 elasticity Tensilestress at yield MPa — — max. MPa 158.68 154.08 break MPa 158.68 154.08T7 2 mm spiral test 23 47 Tensile test: Modulus of MPa 17 246 16 591 ISO527-1 elasticity Tensile stress at yield MPa — — max. MPa 158.68 154.08break MPa 158.68 154.08

The invention claimed is:
 1. A process for producing a moldingcomprising: introducing a melt of a thermoplastic molding compositioninto a mold; introducing nitrogen or compressed air; passing water intothe mold; compressing the nitrogen or compressed air and pressing themelt onto the external walls of the mold; reducing pressure until themold can be opened; wherein the thermoplastic molding compositioncomprises: A) from 10 to 89% by weight of a polyethylene terephthalatewhich can comprise up to 65% by weight, based on 100% by weight of A),of another polyester, B) from 0.01 to 10% by weight of B1) at least onehyperbranched polycarbonate with an OH number of from 1 to 600 mg KOH/gof polycarbonate (to DIN 53240, part 2), or B2) at least one A_(x)B_(y)hyperbranched polyester, where x is at least 1.1 and y is at least 2.1,or a mixture of these, C) from 10 to 60% by weight of a fibrous orparticulate filler, and D) from 0 to 20% by weight of further additives,where the total of the percentages by weight of components A) to D) is100%, and wherein the degree of branching for component B is from 10 to99.9%.
 2. The process of claim 1, wherein nitrogen or compressed air isintroduced at room temperature and at a pressure from 40 to 50 bars. 3.The process of claim 1, wherein water is passed into the mold with aninterval of about 2 seconds.
 4. The process according to claim 1, inwhich component B1) has a number-average molar mass M_(n) of from 100 to15 000 g/mol.
 5. The process according to claim 1, in which componentB1) has a glass transition temperature Tg of from −80° C. to 140° C. 6.The process according to claim 1, in which component B1) has a viscosity(mPas) at 23° C. (to DIN 53019) of from 50 to 200
 000. 7. The processaccording to claim 1, in which component B2) has a number-average molarmass M_(n) of from 300 to 30 000 g/mol.
 8. The process according toclaim 1, in which component B2) has a glass transition temperature Tg offrom −50° C. to 140° C.
 9. The process according to claim 1, in whichcomponent B2) has an OH number (to DIN 53240) of from 0 to 600 mg KOH/gof polyester.
 10. The process according to claim 1 wherein the moldingis a liquid- or gas-conducting pipe, a motor vehicle part, a kitchenequipment, or a coated molding.
 11. The process according to claim 10wherein the molding is a roof railing, stove handle, water pipe, kitchenelement, chair, table leg, strip, profile, exterior mirror, or anattachment system for these, gas pipes, or gas lines.
 12. The processaccording to claim 4, in which component B1) has a glass transitiontemperature Tg of from −80° C. to 140° C.
 13. The process according toclaim 4, in which component B1) has a viscosity (mPas) at 23° C. (to DIN53019) of from 50 to 200
 000. 14. The process according to claim 5, inwhich component B1) has a viscosity (mPas) at 23° C. (to DIN 53019) offrom 50 to 200
 000. 15. The process according to claim 4, in whichcomponent B2) has a number-average molar mass M_(n) of from 300 to 30000 g/mol.
 16. The process according to claim 5, in which component B2)has a number-average molar mass M_(n) of from 300 to 30 000 g/mol. 17.The process according to claim 6, in which component B2) has anumber-average molar mass M_(n) of from 300 to 30 000 g/mol.
 18. Theprocess according to claim 4, in which component B2) has a glasstransition temperature Tg of from −50° C. to 140° C.
 19. The processaccording to claim 5, in which component B2) has a glass transitiontemperature Tg of from −50° C. to 140° C.
 20. The process according toclaim 6, in which component B2) has a glass transition temperature Tg offrom −50° C. to 140° C.
 21. The process according to claim 7, in whichcomponent B2) has a glass transition temperature Tg of from −50° C. to140° C.
 22. The process according to claim 4, in which component B2) hasan OH number (to DIN 53240) of from 0 to 600 mg KOH/g of polyester.